1. Field of the Invention
The present invention relates to an electronic device and, more particularly, to a system having insertable and removable storage and a control method thereof.
2. Description of the Related Art
Electronic devices, especially, portable electronic devices require a low operation voltage to avoid excess heat emission and power consumption. Consumers often desire these devices to be capable of performing many functions that need different amounts of memory. E.g., further to an inherent call function, many portable telephones have a camera function for photographing still images and a camcorder function for photographing mobile images. To smoothly process additional functions together with the inherent functions, the electronic device requires more memory than needed to accomplish simply the call function. Upgradeable flash memory has become a common solution.
As well known, a memory suitable to the portable electronic device is a NAND flash memory. NAND flash memory is packed into an insertable and removable card. Such a card can be inserted into or removed from the portable electronic device according to a user's needs. E.g., a card such as a Multi Media Card (MMC), a Secure Digital card (SD card), a smart media card, or a compact flash card is used to store data for many devices including digital cameras, MP3 players, Portable Digital Assistants (PDAs), handheld personal computers, game players, facsimile machines, scanners, printers, and the like.
As a result, the insertable and removable card must function in many different environments. E.g., the insertable and removable card may be used in an electronic device operating at 3.3V. Alternatively, the insertable and removable card may be used in another electronic device operating at 1.8V. When the card operating at 3.3V is used for the portable electronic device operating at a lower operation voltage, it is impossible to guarantee proper functionality.
Embodiments of the invention address these and other limitations in the prior art.